Conventionally, in a case of optimizing resources of a virtual machine, only the current state of resources is used as disclosed in PTL 1: Japanese Unexamined Patent Application Publication No. 2011-90537, “PROGRAM, APPARATUS AND METHOD FOR CONTROLLING VIRTUAL MACHINE MOVEMENT”, and there is merely provided a function of optimizing the resources of the virtual machine when the resources become very scarce. Such a mechanism addresses the case only after the resources become scarce. Therefore, there is a problem that it is not possible to perform stable operations upon trying to provide services intended for carriers and/or companies, which are required to be provided in real-time like an IP network system such as an IP telephone network.
Further, in a case of performing a live migration where the virtual machine is migrated to a different physical hardware without being stopped, a live-migration destination of the virtual machine is selected only based on the current state of resources. Thus, there is also a problem that even after the live migration, traffic immediately increases at the live-migration destination, which causes a situation where the live migration is repeated, thereby leading to deterioration in performance of the virtual machine or a rapid increase in traffic.